When did you first try Lisp seriously, and which Lisp family member was it?
My first substantive exposure was MacLisp in 1976, running under ITS on a PDP-10. I continued using it on and off for academic projectlets for the next 10 years, even playing around with a small version on an Z-80 I copied out of Byte magazine back in 78. But I'd have to say the first time I actually began using it for real daily work was 1986 using Zetalisp on a Symbolics Lisp Machine.

What led you to try Lisp?
Originally, I was hanging around the MIT AI lab, and one of the hackers there tried to turn me into someone generally useful. (As a side note, I was a contemporary of Kent Pitman, who turned out more useful - to Lisp - than I did - he having an RtL link ;-) Through coursework, I had already been exposed to a kind of lisp in an intro to AI class Sussman tought (not yet called Scheme). As it became clear after leaving school that I wanted to do AI research for my career, I came back to it more and more until I went back to school as a graduate student in 1982. It was "the language" to use for computational linguistics and planning in those days, and my advisor (James Allen) was a pioneer in using planning models to help explain what goes on in conversation.

Where did your road originate?
I guess my first exposure to programming was FORTRAN, then RPG, PDP-10 assembler, MacLisp, PL/I, Algol, SCHEME, Pascal, Z-80 Assembler, then professionally, HP-1000 Assembler (PDP-8), 6800 Assembler, FORTRAN, C, Franz Lisp, ZetaLisp, Common Lisp. On the side I've dabbled with other languages (e.g. programming music software on the Macintosh in the late 80s and early 90s), but always come back to Lisp.

How far have you gotten in your study of Lisp?
Well, I consider myself competent if not expert. I have used CL for a continuation passing scheme in a Knowledge Representation system, I've built intelligent agents, and maybe a dozen kinds of AI systems in CL. I used to dig around in ZWEI and extend it on the Symbolics, at least until Genera came out (when Dynamic Windows was stable enough for UI). And I've built my share of CLIM apps, use CLOS and continuations regularly, even most of the MOP. I use macros frequently to "extend the language" so to speak up to and including triple nested backquotes (macros that write macros). There are a lot of ways to get things done in Lisp, and I'm willing to try almost any way just to learn more, though many techniques I've discarded over the years (e.g., I deplore the loop extensions). I think the most effective tools for learning Lisp (not AI!) were going through the Symbolics source code where I've picked up most of my stylistic preferences, and hanging out in SLUG's mailing list (SLUG eventually became the ALU, but the mailing list is gone AFAIK, oy veh!). I still remember forging a Symbolics Press Release to that list (with a couple of hints it was a forgery) for an April 1st joke about Symbolics releasing their system on Nintendo cartridges (I think it took a couple dozen and you had to swap them :-). At any rate, I've pretty much programmed in nothing else since 1984, and while I don't have the opportunity to program quite so much today, if I do so, it is my language of choice.

What do you think of Lisp so far? If someone would come up with the "sufficintly smart compiler" there would be no reason to ever use any other language! But I've always come into a new job saying "I am a Lisp Hacker," and my employers have always gotten a Lisp for me to hack with. Armtwisting is rarely needed, I simply quote the time to get the job done in Lisp, and then in some other language. :-)